Homes might be large source of water pollution

Homes might be a much-underestimated source of water pollution, according to a new study reported today at the 238th National Meeting of the American Chemical Society.

Researchers Lorence Oki, Darren Haver and colleagues have found that runoff results from rainfall and watering of lawns and gardens, which winds up in municipal storm drains. The runoff washes fertilizers, pesticides and other contaminants into storm drains, and they eventually appear in rivers, lakes and other bodies of water.

“Results from our sampling and monitoring study revealed high detection frequencies of pollutants such as pesticides and pathogen indicators at all sites,” Oki says of the study, which foccussed on eight residential areas in Sacramento and Orange Counties in California.

Preliminary results of the study suggest that current models might underestimate the amount of pollution contributed by homes by up to 50 per cent. That’s because past estimates focused on rain-based runoff during the wet season.

“Use of pesticides, however, increases noticeably during the dry season due to gardening, and our data contains greater resolution than previous studies,” Oki said.

Pollutants detected in outdoor runoff included ant-control pesticide products. Previous surveys have shown that the majority of pesticides purchased by homeowners are used to control ants. To encourage pollutant reduction, the researchers initiated community outreach programs centered on improving both irrigation control and pest management.